util/docker/doc.coreboot.org: Don't create volumes

Volumes are mounted with the command line parameter. Using the VOLUME
directive creates a persistent storage in a standard path, which is not
intended. So drop that and create equal directories in order to keep the
container working.

Change-Id: I9b3551cca34d846aba5ca5c89162f82baa6de768
Signed-off-by: Felix Singer <felixsinger@posteo.net>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/85724
Reviewed-by: Nicholas Chin <nic.c3.14@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

util/docker/doc.coreboot.org/Dockerfile

@@ -14,6 +14,9 @@ RUN \
 	&& chmod 755 /makeSphinx.sh
 
 RUN adduser -D coreboot
+RUN \
+	mkdir /data-in /data-out && \
+	chown -R coreboot:coreboot /data-in /data-out
 
 USER coreboot
 
@@ -31,8 +34,6 @@ RUN \
 		sphinx_autobuild===2024.2.4 \
 		sphinx_rtd_theme===2.0.0
 
-VOLUME /data-in /data-out
-
 # For Sphinx-autobuild
 # Port 8000 - HTTP server
 # Port 35729 - websockets connection to allow automatic browser reloads after each build